Trade fraud, smuggling and terrorism have increased the need for various non-intrusive inspection systems in applications ranging from curb-side inspection of parked vehicles to scanning in congested or high-traffic ports because transportation systems, which efficiently provide for the movement of commodities across borders, also provide opportunities for the inclusion of contraband items such as weapons, explosives, illicit drugs and precious metals. The term port, while generally accepted as referring to a seaport, also applies to a land border crossing or any port of entry.
X-ray systems are used for medical, industrial and security inspection purposes because they can cost-effectively generate images of internal spaces not visible to the human eye. Materials exposed to X-ray (or any other type of) radiation absorb differing amounts of X-ray radiation and, therefore, attenuate an X-ray beam to varying degrees, resulting in a transmitted or backscattered level of radiation that is characteristic of the material. The attenuated or backscattered radiation can be used to generate a useful depiction of the contents of the irradiated object. A typical single energy X-ray configuration used in security inspection equipment may have a fan-shaped or scanning X-ray beam that is transmitted through or backscattered by the object inspected. The absorption or backscattering of X-rays is measured by detectors after the beam has passed through the object and an image is produced of its contents and presented to an operator.
With limited space and a need to expand, finding suitable space to accommodate additional inspection facilities along the normal process route remains difficult. Additionally, selected locations are not necessarily permanent enough for port operators to commit to the long term installation of inspection equipment. Moreover, systems incorporating high-energy X-ray sources, or linear accelerators (LINAC), require either a major investment in shielding material (generally in the form of concrete formations or buildings) or the use of exclusion zones (dead space) around the building itself. In either case, the building footprint requirement is generally too significant depending upon the size of cargo containers to be inspected.
A mobile inspection system offers an appropriate solution to the need for flexible, enhanced inspection capabilities. Because the system is relocatable and investment into a permanent building in which to accommodate the equipment is obviated, site allocation becomes less of an issue and introducing such a system becomes less disruptive. Also, a mobile inspection system provides operators, via higher throughput, with the ability to inspect a larger array of cargo, shipments, vehicles, and other containers.
Conventional inspection systems are disadvantageous in that they suffer from a lack of rigidity, are difficult to implement, and/or have smaller fields of vision. Specifically, conventional relocatable inspection systems generally comprise at least two booms, wherein one boom will contain a plurality of detectors and the other boom will contain at least one X-ray source. The detectors and X-ray source work in unison to scan the cargo on the moving vehicle. In conventional single boom relocatable inspection systems, the X-ray source is located on a truck or flatbed and the detectors on a boom structure extending outward from the truck. These systems are characterized by moving-scan-engine systems wherein the source-detector system moves with respect to a stationary object to be inspected. Also, the detectors and the source of radiation are either mounted on a moveable bed, boom or a vehicle such that they are integrally bound with the vehicle. This limits the flexibility of dismantling the entire system for optimum portability and adjustable deployment to accommodate a wide array of different sized cargo, shipments, vehicles, and other containers. As a result these systems can be complicated to deploy and pose several disadvantages and constraints.
Accordingly, there is need for improved inspection methods and systems that may be rapidly loaded over a truck or a trailer being pulled by any vehicle and transported to a surveillance location for rapid and facile deployment.
There is also need for a portable inspection system that does not require a specialized, expensive transportation vehicle in order to be transported to a surveillance site.
There is a further need for a portable inspection system that is light weight and may be rapidly deployed for inspection.